From Data Realms Wiki
Two examples of ACrab Actors from vanilla CC. On the left we have the literal wildlife crab actor, and on the right we have the Dummy Dreadnought, equipped with a turret that has a mounted Dreadnought MG device.
|Limbs:||4 legs, 1 turret|
|Walking, Operating Mounted Turret Device, Jetpack [unusual]|
|Infobox Template: ActorClass|
ACrabs are quadrupedal actors derived from the Actor class. Their name is an amalgam of Actor and Crab, although real crabs typically have more than four legs. The term crab is used because this actor type was originally made for crabs, which are depicted in CC as quadrupedal, likely for the sake of simplicity.
An ACrab has the benefit of added ground mobility, having four legs and no upright constraints, but they are not typically equipped jetpacks. ACrabs are capable of having a jetpack, but it is uncommon. Their lack of upright constraints affects their jetpack use.
Their angle of fire can be limited, making upper and lower bounds to the angle they can aim (like real-world tanks). However, the bounds are not in relation to the rotation of the actor.
Instead of arms like AHumans have for operating devices, ACrabs have a turret with a mounted device. This limits them to that single predetermined device. They can not switch devices, pick up devices, or drop devices. Their one and only device can be and generally is destructible. While they can hold devices in their inventory, they cannot access them, they will only serve to weigh them down, and they will only be retrievable upon the ACrab gibbing. ACrabs oddly do not suffer from recoil forces, this was likely an oversight in the creation of their means of handling a device. They are commonly used to make bombs by filling a rocket with them, due to them being free.
For an example of an ACrab, click here.